So that's still, $17,000.00, if i were you I'd be ringing around a having a chat to some other builders - unfortunately you're in a sh*t situation, and I feel soooo much for you
Don't give up until you've explored all your options under the circumstances it may also be nice to have a fresh start...
I didn't realise this Jess! (but then i'm in WA and not a first home buyer/builder )
So all would not be lost if the OP did turn down this builder!